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| | =A, B, Cs of Lunar Topography= | | =A, B, Cs of Lunar Topography= |
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| + | <p>[[File:CatDepth-DiamLPOD.jpg|CatDepth-DiamLPOD.jpg]]<br /> |
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| − | <p>[[File:CatDepth-DiamLPOD.jpg|CatDepth-DiamLPOD.jpg]]<br /> | |
| | <em>image by [mailto:tychocrater@yahoo.com Chuck Wood], Wheeling, WV</em></p> | | <em>image by [mailto:tychocrater@yahoo.com Chuck Wood], Wheeling, WV</em></p> |
| | <p>This is the most boring LPOD image of the year. But it demonstrates a need and an opportunity. The excerpt of a spreadsheet above lists 43 craters and their diameters and depths. Of these, 5 (or 12%) have two measures of diameters that disagree (yellow) by more than 5-10%; surely, we can determine if Alphonsus is 108 or 119 km wide? And for 13 of the craters (30%), estimates of depths disagree by 1 to 2 km! Is Abulfeda 1.2 km deep or 3.2? And this list doesn’t include craters where no depths are available at all! Recently, three amateurs - Kurt Fisher, Jim Mosher and Henrik Bondo - have contributed tools that allow a new evaluation of lunar topography. [http://members.csolutions.net/fisherka/astronote/plan/craterdepth/CraterDepthsApolloEra.html Kurt] has industriously compiled digital databases of previous measurements of lunar crater depths and diameters, from which I constructed the figure above. And the <em>Lunar Terminator Visualization Tool</em> [http://inet.uni2.dk/~d120588/henrik/jim_ltvt.html software] created by Jim and Henrik provides the easiest way ever to measure lunar dimensions. Add to these tools the annual production of hundreds of high resolution lunar images by talented observers and everything needed for a revolution in lunar topography is at hand. (A) I encourage individuals to continue to acquire high res lunar images - especially near enough to the terminator so that crater rim shadows fall on their floors. (B) I encourage someone/s to create a complete catalog such as the sample above that identifies where dimensional measures are needed either because they are missing or existing data conflict. (C) And I encourage various people to become proficient enough with LTVT so that they can routinely determine high precision crater diameters and depths. Following these As, Bs and Cs a comprehensive catalog of accurate lunar crater dimensions can be compiled. Similarly, heights and slopes of peaks, domes, scarps, rilles and central peaks can be determined. Four hundred years after Galileo first estimated sizes of lunar features, we still don’t have comprehensive cataloging of lunar topography, but now it is possible for amateurs to do the job!</p> | | <p>This is the most boring LPOD image of the year. But it demonstrates a need and an opportunity. The excerpt of a spreadsheet above lists 43 craters and their diameters and depths. Of these, 5 (or 12%) have two measures of diameters that disagree (yellow) by more than 5-10%; surely, we can determine if Alphonsus is 108 or 119 km wide? And for 13 of the craters (30%), estimates of depths disagree by 1 to 2 km! Is Abulfeda 1.2 km deep or 3.2? And this list doesn’t include craters where no depths are available at all! Recently, three amateurs - Kurt Fisher, Jim Mosher and Henrik Bondo - have contributed tools that allow a new evaluation of lunar topography. [http://members.csolutions.net/fisherka/astronote/plan/craterdepth/CraterDepthsApolloEra.html Kurt] has industriously compiled digital databases of previous measurements of lunar crater depths and diameters, from which I constructed the figure above. And the <em>Lunar Terminator Visualization Tool</em> [http://inet.uni2.dk/~d120588/henrik/jim_ltvt.html software] created by Jim and Henrik provides the easiest way ever to measure lunar dimensions. Add to these tools the annual production of hundreds of high resolution lunar images by talented observers and everything needed for a revolution in lunar topography is at hand. (A) I encourage individuals to continue to acquire high res lunar images - especially near enough to the terminator so that crater rim shadows fall on their floors. (B) I encourage someone/s to create a complete catalog such as the sample above that identifies where dimensional measures are needed either because they are missing or existing data conflict. (C) And I encourage various people to become proficient enough with LTVT so that they can routinely determine high precision crater diameters and depths. Following these As, Bs and Cs a comprehensive catalog of accurate lunar crater dimensions can be compiled. Similarly, heights and slopes of peaks, domes, scarps, rilles and central peaks can be determined. Four hundred years after Galileo first estimated sizes of lunar features, we still don’t have comprehensive cataloging of lunar topography, but now it is possible for amateurs to do the job!</p> |
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| | There are many details yet to be given about the list above and how to accurately measure shadow lengths. If there is interest in doing this work - individuals can work alone or collaborate - I can write more explicit suggestions.</p> | | There are many details yet to be given about the list above and how to accurately measure shadow lengths. If there is interest in doing this work - individuals can work alone or collaborate - I can write more explicit suggestions.</p> |
| | <p><strong>Related Links:</strong><br /> | | <p><strong>Related Links:</strong><br /> |
| − | [http://www.lpod.org/?m=20061211 Crater depths]</p> | + | [[December_11,_2006|Crater depths]]</p> |
| − | <p align="center"> | + | <p><b>Yesterday's LPOD:</b> [[December 14, 2006|1 Eclipse, 2 Telescopes & 58 Images]] </p> |
| − | <i>Christmas is coming - consider leaving a list of lunar books on top of a spouse’s pillow - just make sure you include the LPOD URL so that you support [http://www.lpod.org/?page_id=591 LPOD] when buying lunar books (or ANY book) from Amazon!</i></p> | + | <p><b>Tomorrow's LPOD:</b> [[December 16, 2006|Land of Milk and Honey and Rilles]] </p> |
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| − | ===COMMENTS?===
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